Clearing timer system for oven controls



June 11, 1968 J. R. WILLSON TIMER SYSTEM FOR OVEN CONTROLS CLEARINGOriginal Filed July 19, 1961 9 Sheets-Sheet 1 NQ vmm 7 H m $8 N m N QEINVENTOR. JAMES R. WI LLSON HIS ATTORNEY June 11, 1968 J. R. WILLSON3,387,780

CLEARING TIMER SYSTEM FOR OVEN CONTROLS Original Filed July 19, 1961 9Sheets-Sheet :5

June 11, 1968 J. R. WILLSON 3,387,780

CLEARING TIMER SYSTEM FOR OVEN CONTROLS Original Filed July 19, 1961 9Sheets-Sheet 4 FIG-7 FlG-8 INVENTOR. JAMES R. WI LLSON HIS ATTORNEY June11, 1968 J. R. WILLSON 3,387,780

CLEARING TIMER SYSTEM FOR OVEN CONTROLS Original Filed July 19, 1961 9sheets-sheet 5 use I90 I92 E F I 4%, I78 I76 :::ud 174 T I88 i I88INVENTOR. JAMES R. W! LLSON HIS ATTORNEY June 11, 1968 J. R. WILLSONCLEARING TIMER SYSTEM FOR OVEN CONTROLS 9 Sheets-Sheet 6 Original FiledJuly 19, 1961 INVENTOR. JAMES R. W l LLSON H IS ATTORNEY 1968 J. R.WILLSON CLEARING TIMER SYSTEM FOR OVEN CONTROLS Original Filed July 19,1961 June 11 9 Sheets-Sheet 7 FIG-l8 FIG-i9 FBG'ZI FIG-2O INVENTOR JAMESR.

WILLSON HIS ATTORNEY June 11, 1968 J. R. WILLSON CLEARING TIMER SYSTEMFOR OVEN CONTROLS Original Filed July 19, 1961 9 Sheets-Sheet 8 @m mmmmmmn FIG'23 FIG-25 INVENTOR. JAMES R. WI LLSON H 18 ATTORNEY June 11,1968 J. R. WILLSON 3,387,780

CLEARING TIMER SYSTEM FOR OVEN CONTROLS Original Filed July 19, 1961 9Sheets-Sheet 9 THERMOSTAT I06 4|8 4|6 AND THE LIKE a v 412 436MANIPULATOR TIMER MOTOR FlG-Z 432 Fir/436 437 INVENTOR. 438 JAMES R. WILLSON FIG-32 VATTORNEY 3,387,789 CLEARENG Til ER SYSTEM FOR OVENCQNTRGLS James R. Willson, Greensburg, Pa., assignor to RobertshawControls Company, a corporation of Delaware Continuation of abandonedapplication Ser. No. 416,184,

Nov. 23, 1964, which is a continuation of application Ser. No. 125,138,July 19, 1961. This application Apr. 10, M67, Ser. No. 629,329

29 Claims. (Cl. 236-46) AfiSTRACT 9F THE DISCLOSURE This disclosurerelates to a control means that can be manually set to tend to maintainthe temperature efiiect of a heating means at a selected temperatureeffect until a heat motor of the control device is activated whereby theactivated heat motor will automaticaLy adjust the control device to tendto maintain a second temperature effect of the heating means until themanual manipulator means of the control device is moved to its offposition, the manual manipulator means of the control device is moved toits off position, the manual manipulator means of the control device ismoved to its off position, the manual manipulator means of the controldevice being adapted to set the control device in its 01? position tostop the operation of the heating means before and after the heat motorhas adjusted the control device to the different temperature settingthereof.

This application is a continuation of patent application S.N. 416,184,filed Nov. 23, 1964, now abandoned, which is a continuation of theco-pending patent application, S.N. 125,38, filed July 19, 1961, and nowabandoned.

This invention relates to the temperature control of heated spaces, suchas cooking ovens, and the like.

One of the features of this invention includes a relatively simple andeflicient thermostatic unit having a thermostat on-and-off manipulatorwhich unit is used in connection with a relatively simple timer having atimer knob which is manually movable from an off position to a pluralityof on positions, such as a combined thermostat tim r controlled heatingzone, and the like. After the timer knob has been moved to any of suchon positions, the knob and the timer mechanism controlled thereby arereturned by a motor and the like to the off position. While soreturning, the knob and mechanism governed thereby may cause thethermostat unit to control a heater in the space being heated to producea normal heating temperature, such as a normal cooking temperature inthe oven for the period time selected by the setting of the timer knob.When the knob and mechanism controlled thereby return toward the timeroff position, they may enter a thermostat unit modifying position wherethe timer modifies the setting, condition, or the operation of thethermostat unit to cause the thermostat unit, for example, to produce atemperature lower the temperature produced in the normal previous periodof time. The timer pauses in this position and holds this operation inmodified condition until the user desires to terminate the entireheating procedure. To do so, the user may then turn the thermostatmanipulator to the off position, whereupon the timer automatically movesto its own timer off position and automatically de-energizes itself, sothat both the heating operation and the timer operation are stopped, andthe system is placed in condition for adjustment for any desired futurecooking operation.

The foregoing operation is particularly useful when it is desired tocook food in the oven for a predetermined tates Patent or selectednormal thermostatically controlled period of time, which may be obtainedby turning the thermostat manipulator to a desired temperature onposition and by turning the timer to a selected timed period of timeposition, such as a period of two hours or the like. The food is thencooked in the oven at the desired thermostatically controlledtemperature until the expiration of such selected period of time,whereupon the operation of the system may be modified, as by modifyingthe operating temperature of the system automatically to a reducedwarming, or heat holding temperature which holds the food at the desiredlower temperature indefinitely while the remainder of the meal is beingprepared or consumed. When the time arrives when the food in the oven isto be removed from the oven, the user then turns the thermostatmanipulator to the off position at about the time when the food is beingremoved or has been removed. When the manipulator is turned to the offposi tion, the heater is die-energized, and the timer knob isautomatically caused to move to its own timer off position and the timerto become de-energized at such timer knob off position, completely tode-energize the entire system and to place it in readiness for somedesired future use.

This type of cooking operation is also advantageous where a meal hasbeen timed and prepared for an expected time of service; but someunexpected delay, such as late arrival of guests and the like, delaysthe serving of the meal. The modified or lower temperature setting ofthe thermostat unit, automatically reduces the temperature maintained inthe oven to maintain the contents of the oven at the best possibletemperature to hold the food in readiness whenever it is finallypossible to serve the meal at such delayed time.

Instead of modifying the temperature to be maintained by the thermostatunit during the modified period of time, a different type ofmodification may be provided for the thermostat unit. For example, thethermostat manipulator may be automatically returned to the off positionby such modifying action and this in turn may cause the timer knob toproceed to the oil position and to turn the timer off, so that theentire cooking operation is terminated and the thermostat unit and thetimer are placed in off posiions in readiness to be used again under anydesired conditions.

Another feature of this invention is to provide a modifying temperatureaction for a thermostat unit, such as a lower temperature setting oroperation. Such modifying action may be performed by a heat motor, anelectromagnetic action, or the like which may be caused to operate whenthe timer knob reaches the modifying position. When the heat motor, forexample, is heated, such heat motor automatically changes thethermostatic setting of the thermostat unit to produce a differenttemperature conrol. For example, such heat motor may cause thethermostat unit to produce a lower temperature in the oven or otherspace than the previous or normal temperature which the thermostat unithad been producing in accordance with the thermostat manipulatorsetting.

Another feature of this invention is the provision of the thermostatunit which may be operated or produced without the temperature modifyingunit, such as the heat motor, so the thermostat unit may be sold orproduced for use without such modifying unit, when desired.

Another feature of this invention is to provide improved automaticcontrols or manual controls for a gas heater and the like. According tothis invention, the gas heater or heating arrangement may include a maingas burner and a pilot burner. The main gas burner may be fed with maingas burner gas through a main gas burner thermostat valve. The pilotburner may be fed with pilot gas at a rate to produce a small pilotflame or pattern and a large pilot flame or pattern, depending upon thecontrol conditions imposed on such pilot burner. The temperatureresponsive element of the main gas burner thermostat valve-is sopositioned that it is only responsive to the production of the largepilot flame or pattern and is not effective to open the valve exceptwhen such large flame or pattern is produced. It is therefore possibleto produce a relatively simple and small pilot gas controller whichcontrols only the pilot gas flow to control the temperature of thecompartment to be heated by a main gas burner. This pilot control causesthe pilot burner to produce a small flame or pattern when no heating isdesired from the main gas burner, and to produce the relatively largepilot flame of pattern when heat is desired from such main gas burner.If desired, the pilot gas flow may be controlled by a thermostat unit ofthis invention. Such a thermostat unit may be relatively small andsimple, as it is only required to control pilot gas.

Another feature of this invention is to provide a relatively small andeifective thermostat unit which has an operationally fixed pilot gascontrol means to feed pilot gas to a pilot burner at a rate to produce arelatively low pilot flame or flame pattern. The thermostat unit alsohas an operationally variable pilot gas control to feed pilot gas tosaid pilot burner to produce a relatively high pilot flame or flamepattern, preferably in response to temperature conditions produced bythe main gas burner of the installation. Such thermostat unit maycontrol thermostatically the operation of the variable pilot gas controlto cause the flame of the pilot burner to turn on and off the main gasburner construction as elsewhere described.

Another feature of this invention is to provide a thermostat unit forthermostatically controlling the operation of a heater, which thermostatunit has switch constructions to be connected with switch constructionsin a timer to cause the timer to control the operation or to time theoperation of the thermostat unit through the medium of such switchconstructions. The timer preferably is of the type which is manually setfrom its off position to a selected timed operation position and thenreturns automatically to its off position. In addition, if desired, suchswitch constructions may also cause indicating devices to indicate thecondition of the system being controlled, and if desired, to cause thethermostat unit to be modified or stopped, and to cause the timer to bestopped and be returned to its on? position.

Another feature of this invention includes a thermostat unit which has arotatable thermostat manipulator and a shaft with a threadedconstruction fixedly secured to th manipulator and being rotatablethereby to move Such shaft axially while being rotated. This shaft isconnected by a rotationally fixed, axially slidable joint to a fulcrumpin which has a thermostat arm fulcrum axially movable by axial movementof said shaft to desired temperature positions in one axial direction.Said fulcrum also is freely movable beyond such desired positions inthat direction by the free movement caused by said slidable joint. Athermostat arm is fulcrumed on such a fulcrum and is operated by athermostat element which rocks the arm about such fulcrum. An energycontroller, such as a valve and the like, is operated by the thermostatarm in response to temperature conditions of the thermostat element. Amodifying construction moves the fulcrum beyond the desired temperaturepositions set by the manipulator to modify the temperature controllingoperation of the unit. Such modifying construction may be electricallyoperated, such as by an electrically energizing heat motor.

Accordingly, it is among the many objects of this invention to provideconstructions and methods embodying one or more of the features hereinset forth.

Other objects are apparent from this description and/or the accompanyingdrawings in which:

FIGURE 1 is a schematic and diagrammatic view of the invention asapplied, for example, to a gas range, and indicating the oven as havingbeen preheated to a selected 4 heat temperature, such as 300, with theoven ready to receive articles to be cooked, and with the timer ready tobe set to a desired timed automatic temperature, or alternately, for theoven to be operated under thermostatic control Without timer control, asdesired.

FIGURE 2 is a view similar to certain portions of FIGURE 1, and showingthe timer as having been set to position 2 ready to time the bakingoperaton for two hours or the like.

FIGURE 3 is a view similar to FIGURE 2, and show ing the timer as havingreached a position just prior to zero.

FIGURE 4 is a view similar to FIGURE 3, and show ing the bakingoperation as having reached the zero position of the timer.

FIGURE 5 is a view similar to FIGURE 4, and showing the thermostat ashaving been set at the oil position, and the timer being driven to thetimer off position, but not quite having reached it.

FIGURE 6 is a view similar to FIGURE 5, but showing the thermostat inthe off position, so the timer may be operated as a timer only suitablefor timing any operation such as a surface unit cooking operation andthe like.

FIGURE 7 is a longitudinal cross section of the thermostat control unit,with the parts shown near the off position of the dial.

FIGURE 8 is an end view of the unit, with the manipulator, bezel andcertain other end parts removed.

FIGURE 9 is a cross section of the sleeve which produces axial movementupon rotation of the manipulator of the thermostat.

FIGURE 10 is a side view of the thermostat arm fulcrum piece, which ismoved longitudinally mainly by the action of the sleeve of FIGURE 9.

FIGURE 11 is an end view of the lower end of FIG- URE 10.

FIGURE 12 is a side view of a portion of FIGURE 11.

FIGURE 13 is a side view of the calibration screw for calibrating thesetting of the manipulator with respect to the action of the thermostatarm.

FIGURE 14 is a cross section of a portion of the thermostat cast body onwhich the rotation limiting pin of FIGURE 10 rides during rotation.

FIGURE 15 is an enlarged end view of FIGURE 14 taken along the line15-45 of FIGURE 14.

FIGURE 16 is a cross section of the off cam of FIG- URE 15 developedalong the circular line I616 of FIGURE 15 FIGURE 17 is a view somewhatsimilar to FIGURE 8, but showing the end view of the thermostat with theheating unit removed, and indicating certain gas flow paths.

FIGURE 18 is a partial cross section substantially along the line 18-18of FIGURE 17.

FIGURE 19 is a cross section substantially along the line 1919 of FIGURE17.

FIGURE 20 is a cross section substantially along the line 20-40 ofFIGURE 17.

FIGURE 21 is a cross section substantially along the line 21.21 ofFIGURE 17.

FIGURE 22 is a diagrammatic representation showing a certain switch inthe off position of the thermostat manipulator or in the overshootposition of the thermostat arm.

FIGURE 23 is a view similar to FIGURE 22, but showing said certainswitch in closed position, as when the thermostat arm is at or near theselected temperature.

FIGURE 24 is a view similar to FIGURES 22 and 23 but showing saidcertain switch at a temperature substantially below the selectedtemperature.

FIGURE 25 is an end view of a suitable cam for the timer, the switchesoperated thereby, and the linkage used to operate the switches.

FIGURE 26 is a diagrammatic side View of the time! and the driving motortherefor.

FIGURE 27 is a diagrammatic representation of a timer knob of anotherembodiment.

FEGURE 28 is a wiring diagram of a system with the timer snob of FiGURE27.

FIGURES 2932 are wiring diagrams similar to FIG- URE 28, showing otherstages during the travel of the timer knob of FIGURE 27.

FIGURE 33 is a diagrammatic iilustration of a manipulator for a unit tobe used with the timer of FIG- URES 27-32.

In FIGURES 1-6, etc., the wiring diagrams show the electric wires orconnectors in heavy lines only where electric current is flowing and theremaining wires or connectors, in which the electric current is staticor not flowing, are shown in dotted lines. There is no electricalconnection where the illustrated lines cross each other except where arelatively heavy dot has been added to indicate an electricalconnection. The various switches have been diagrammatically illustratedas of the slow make and break type, but it is to be understood thatother types of switches may be used, which may be of the fast or snapmake and break type, as desired. The diagrammatic showings of theswitches are intended to indicate that any suitable type of switch maybe used. Some of the relatively stationary contact blades are shown asheld by an insulating block or the like, to make the stationary natureof such blades more readily apparent.

For convenience in description, certain words of directional descriptionare used, such as upward, downward, vertical, horizontal, etc. Thesewords are used in connection with the directions shown in the drawings.However, the members in actual use may have different directions fromthose illustrated and described.

One embodiment of this invention is illustrated in FIGURE 1, which showsdiagrammatically how this invention may be applied, for example, to anoven 30, which may be the oven of a kitchen range which may use gas asthe heating medium. The oven 30 may have a baking compartment 32 and abroiling compartment 34. A gas burner 36 is placed between the bake andbroil compartments and is fed gas through the pipe 38 under the controlof the thermostat control unit 40 and in response to the temperature ofcompartment 32 and the position of the manipulator or handle 42, whichmay be turned about the axis 44 to any desired temperature or onposition with respect to the stationary pointer 46.

The gas may be fed to the main burner 36 under the control of thethermostat unit 40 by any well-known means or arrangements now known forthis type of control, in a manner to maintain a selected temperature inthe oven compartment 32 in response to the setting of the manipulator 42to a selected position.

However, according to a preferred embodiment of this invention, theheating action of the main burner or heater 36 may be controlled bycontrolling the flow of pilot gas only through the thermostat unit iii.The pilot gas iS caused to produce a small pilot flame when no heatingby burner 36 is required, and to produce a large pilot flame whenheating by burner 36 is required. The main burner 36 is automaticallylighted when the pilot flame is large and is extinguished when the pilotflame is small.

To this end, pilot gas may be fed into the body of the thermostat unit49 through the pipe 48. A portion of this gas may then flow throughsuitable passageways in the unit 40 so that a portion is fed to thepilot supply pipe 5i? under a manually set throttling action to providean operationally fixed pilot gas control. Another portion of the pilotgas is fed through suitable thermostatically controlled passageways inresponse to thermostatic control in the unit 40 according to the settingof the manipulator 42. This last portion of pilot gas is also fed to thepilot supply pipe 56. The pipe 50 feeds the pilot 53, the end of whichmay be ignited to form either a small pilot flame or flame pattern 54 ora large pilot flame or flame pattern 55. The flames 5'4 and 55 may befed with pilot gas through a single orifice, if desired. The small pilotflame 54 is intended to be continuously ignited under a standbycondition, at which time gas is fed only through the passageways in theunit 40 which have manually set constant conditions, more fullyelsewhere described. These constant conditions may be periodicallyadjusted, however, to obtain a small pilot flame 54 of desired size.When the temperature in the compartment 32 is below the temperatureselected by the setting of the manipulator 42, the thermostat bulb 56causes gas to be fed to the pipe 50 and pilot burner 53 at a slightlyhigher pressure than is produced by the manually set constantconditions, and produces the larger pilot flame 55.

The production of the larger flame 55 in turn heats a thermostat bulb57, which may be a mercury bulb, if desired, which opens the main burnervalve 58 to feed main burner gas from the pipe 38 into the main burner36. The main burner 36 is ignited by the pilot flame 55. On the otherhand, when the temperature in compartment 32 rises in response to theheat produced by the main burner 36, then the thermostat bulb 56 and theunit 40 cut off the thermostatically controlled, higher volume pilot gasflow to the pipe 50, so that the rate of flow in the pipe 50 and pilot53 produces only the small pilot flame 54. This permits the thermostatbulb 57 to cool sufliciently to close the valve 58 and thus to turn offthe main burner 36. This turning on and off of the main burner 36 inresponse to the temperature of the bulb 56 continues as long as isdesired by the user.

The thermostat bulb 57 is suitably insulated from the effects of theheat produced by main burner 36 so the heat from the burner 36 isinsufficient to maintain the valve 58 open in the absence of the heatfrom large pilot flame 55. The bulb '57 require high heat from flame 55.Consequently, the feed of gas to burner 36 is stopped whenever the largepilot flame 55 is not produced.

The user may choose to operate the system either under the control ofthermostat unit 40 only, or under the combined timer and thermostat unitcontrol which is elsewhere described. The timer may be usedindependently of the thermostat unit 41 to indicate a time cycle forsome other operation on the stove or elsewhere.

Suitable safety features are provided to prevent the feeding of unburnedgas into the oven if the pilot flame 54 should be extinguished oraccidentally should not be ignited. For this purpose, a safety valveconstruction 59A may be provided which turns off the discharge of gasinto the entire oven system illustrated whenever the pilot flame 54 (orflame 55) is not burning. The valve construction 59A is made so that itcloses and cuts oif the feed of pilot gas to pilot 53 whenever thethermocouple 69 is not heated by the flame 54. To this end, anelectromagnet 61 is energized by thermocouple electric current wheneverthe thermocouple 60 is properly heated by the flame 5d and maintains themagnetic armature 62 in the upward position, as shown in FIGURE 1, andwith the valve 59 in an upward position to permit gas to flow from thepilot pipe 50 to the pilot burner 53. However, should the thermocouple60 become relatively cold by not being heated by the flame 54, then themagnet 61 becomes sufiiciently electrically de-energized because of thereduction of thermocouple electric current and releases the armature 62for downward movement. The compression spring 64 pushes the knob 65downward and simultaneously pushes the valve 59 against the valve seat66 completely to turn off the gas from the pilot burner 53. The pilotburner then cannot produce either the small pilot flame 4 or the largepilot flame 55. The main burner thermostat 57 consequently cannot beheated and cannot open the main burner valve 58. Therefore, unburned gascan not be discharged into the oven either by the pilot 53 or the mainburner 36.

When it is desired again to start the system or to reignite the flame54, the push button 65 is pushed upward, so that the armature 62 isplaced adjacent the magnet 61.

7 This permits the flow of gas to the pilot 53, which may then beignited. The knob 65 is held pushed in for about seconds to permit thethermocouple to become sufficiently heated to energize the electromagnet61 to hold the armature 62 in the upward position. The system may thenoperate under normal conditions.

The pilot flame 54 is intended to be continuously operating understandby conditions and is expected to remain ignited unless some defecthas occurred in the system. Such defect should be rectified beforeattempting to reignite the pilot 53. The ignition procedure by pushingof the knob 65 upward for thirty seconds or more is only performedinitially to ignite the flame 54, after which the system may be inreadiness continuously for the cooking operations which are elsewheredescribed.

The thermostat unit 40 causes main burner gas to be fed to the mainburner 36 in response to temperatures in the oven compartment 32 tomaintain the compartment 32 at the temperature selected by thepositioning of the manipulator 42. Alternatively, when the manipulatoris turned to the broil position, the gas is fed through the pipe 38substantially continuously because of the very high temperature settingof the manipulator 42 so an or cient broiling operation is performedwhen food is placed in the broiling compartment 34 under the burner 36.

The compartments 32 and 34 may be provided with independent doors 33 and35, of well known construction.

The thermostat unit 40 is responsive to the temperatures in thecompartment 32 through the medium of the thermostat bulb 56 which isplaced in the oven 30, and which contains a suitable thermostat fluid,either gaseous or liquid. The pressure is transmitted through the tube66 to the expansible and contractable diaphragm or bellows 68 to rockthe thermostat arm 70 about the fulcrum point or platform '72. The arm70 pushes against the valve plunger 74 and raises or lowers such plunger74 to open or close the valve 76, FIGURE 7, against the action of spring78, thus to cover or uncover the valve seat and to permit or stop theflow of pilot gas from the passageway 82 and pipe 48 to the passageway84, which in turn discharges such gas into the pipe 50, while anotherstream of pilot gas is passing through other passageways to bedescribed, which also discharge into the pipe 50.

A timer 86, FIGURE 1, has a handle or knob 88 which may be allowed toremain at the off position 90, as shown in FIGURE 1, so that the oven 30and the thermostat unit 40 may be operated independently of the timer86. A baking operation may then be performed and timed independently ofthe timer by the operator. Alternatively, the operator may elect to usethe timer to aid in governing a preheating operation of the oven, aswill now be described.

Some of the other possible operations are shown in FIGURES 2-6.

If the user desires to bake or broil food in the oven 30 under thecontrol of the thermostat unit 40, but not under the control or timeindication of the timer 86, the timer knob or handle 88 is placed in theoff position 90, as illustrated in FIGURE 1, as more fully explained inthe following description.

Manual operation, with thermostat only, FIGURE 1 The timer handle 88 isconnected by a shaft or the like to the switches 92, 94, and 96. Theswitch 96 is closed or down at all handle 88 positions except atposition 90 at which time switch 96 is in open position, or up position,of FIGURE 1. Switch 94 is in up position, FIGURE 1, while timer handleis in the zone between 108 and 90 to close contacts 322, 324 and 318,320. Switch 92 is in up position While handle 88 is in zone 106, butswitch 92 is in down position at all other times, as shown in FIGURE 1.

The user may place the manipulator 42 of the thermostat unit 40 at anydesired position, such as a bake position, from 170 to 550, for example,or at the broil position, which is a very high temperature setting wellabove any temperature normally attainable under baking conditions. Theuser may then proceed to bake or broil, as is usual with ranges providedwith a thermostat unit of prior constructions. In the off position 90 ofthe timer 86, the timer 86 does not interfere, or modify the operationof the thermostat unit 40 in any manner whatsoever, except that, ifdesired, it positions the switch 94 of the timer 86 in the up positionso when the manipulator 42 is turned to an on position, such as 300, thelight 98 can be intermittently illuminated and the oven on light 100 isilluminated. The light 100 is illuminated continuously by closedcontacts 246, 247 of switch 240 and the light 98 is illuminatedintermittently when the oven temperature in compartment 32 passes up anddown past the selected temperature, such as 300 as illustrated in FIGURE1, intermittently to close contacts 260, 262 of switch 264. Such light98 is not illuminated when the compartment 32 temperature and bulb 56are either substantially below the selected temperature or substantiallyabove the selected temperature, and is illuminated when the ovencompartment is substantially at the selected temperature as is elsewheremore fully described in conncction with FIGURES 22, 23 and 24. The light100 indicates that the oven is being heated, and light indicates thatthe oven heating is under automatic control of unit 40 and timer 8 5, aselsewhere described.

Hence, it is to be seen that the user may operate the oven 30 under thecontrol of the thermostat unit 40 without any timing guidance or controlfrom the timer 86 when the timer handle is at 90, as shown in FIGURE 1.

Automatic operation under joint control and indication of timer andthermostat unit, FIGURES 15 The user may perform an oven cookingoperation under the control of the thermostat unit 40 and under properindications and control from the timer 86.

The user may perform a preheating operation of the oven, without anyfood in it, until the oven temperature reaches the selected temperature,as selected by the position of the manipulator 42. This preheatingoperation may be performed under switch conditions of FIGURE 1, untilthe oven reaches 300 or other selected temperature, which causes light98 to be illuminated. Thereafter, the user may insert the food into thecompartment 32 and set the timer handle 88 for any desired period ofnormal thermostatically controlled operation subsequent to the insertionof the food. This type of operation is preferred by many users. This maybe accomplished by first setting the timer knob 88 and the thermostatunit knob 42 in the positions shown in FIGURE 1, to produce a preheatingaction prior to the insertion of food in the oven 30.

With the controls set as indicated in FIGURE 1, the oven is permitted tocome to preheat to the selected temperature, such as 300, which ischosen merely by way of example. During this preheating operation, theoven light 100 is continuously illuminated by closed contacts 246 and247 but the light 98 remains dark until the oven has reached the 300 orother selected temperature, at which time the light 98 illuminates for ashort period of time until the arm 70, at its outer end 70A, overshootsupward above the valve plunger 74, which causes the light 98 to beturned off by the opening of switch 24 and it will remain dark until theoven has cooled substantially to the selected temperature when the light98 again illuminates temporarily and continues to flick on and off bythe opening and closing of switch 264 as the temperatures rise and fallslightly above and below the selected temperature, such as 300 inresponse to the thermostatic control by unit 46. This indicates to theuser that the oven is now properly preheated and that the oven is readyto receive the food.

Thereupon the user inserts the food in the compartment, such ascompartment 32, and then sets the timer 86 to the desired normal cookinginterval of time, such as to two hours, as shown in FIGURE 2. The foodthen will be cooked in the oven while the knob or handle 88 proceeds toreturn clockwise until it reaches the position 102 and zone 186, FIGURE3, which closes contacts 306, 308 and which causes the buzzer 104 tosound for seconds, while the knob or handle 88 is passing the zone 106.This continues substantially until a time just before the knob 88reaches the zero position 108 at the end of zone 106, at which time thebuzzer ceases to operate because contacts 306 and 398 are opened at theend of zone 106.

During the time that the handle 88 is moving from position 2 to position102, the buzzer 104 is not sounded, as shown in FIGURE 2, but the lights100 and 110 are illuminated by the closed switches 246, 247 and 310, 312to indicate that the oven is operating under thermostatic and timercontrol and that automatic operation is being provided, as indicated inFIGURES 2 and 3.

When the knob 88 reaches the position 108 as shown in FIGURE 4, themotor 112 of the timer stops, because of open contacts 314, 316 and 250and 252, thus causing the timer to stop. The light 98 illuminatesintermittently to indicate that the elapsed time or higher temperaturecooking has been completed. Just before this time the buzzer 104 alsohad been operating for 15 seconds while handle 88 was passing zone 106,in FIGURE 3.

Modification, such as a change to a lower temperature for final periodof cooking When the higher temperature or normal cooking operationreaches the stage with timer knob at 108, as illustrated in FIGURE 4,the timer 86 causes the thermostat unit to be modified, such as by beingadjusted automatically to operate at a lower controlled temperature,which cooking operation will continue indefinitely until the user turnsthe thermostat unit manipulator 42 to the off position of FIGURE 5.

However, while the controls are still in the positions indicated inFIGURE 4, the heat motor 114 is heated by the energization of the heater116, by the closed contacts 246, 247 and 310, 312 and 322, 324, in amanner automatically to set the unit 40 at a lower temperature than thatindicated by the knob 42. This may be a warmth retaining temperature, ifdesired.

The heating of the heat motor 114 causes the lever 118 to be raised bythe ball or pusher 220 of the heat motor, so the lever 118 swings aboutthe fulcrum point 122 and raises the fulcrum point or platform '72 ofthe unit 40 to a higher position or until the lever 118 is stopped bythe stop member 124. In this manner the fulcrum point 72 is set at theequivalent of a much lower temperature than the setting by manipulator42 and this causes the thermostat valve 76, FIGURE 7, which is operatedby the plunger 74, to operate at this lower temperature range.

At this lower temperature operation, the light 98 and the buzzer 104,FIGURE 4, are intermittently energized by intermittently opened andclosed contacts 260, 262, as elsewhere described, to warn the user thatthe dinner is about to be ready for serving. For example, the user maypermit this lower temperature cooking or warming operation to continuefor twenty to thirty minutes. When the user is ready to serve thedinner, the user turns the thermostat manipulator 42 to the offposition, as indicated in FIGURE 5. This causes the timer motor 112 tobe energized and to drive the timer handle 88 to the final otl position99, as in FIGURE 1, and to cause the thermostat valve 76 to becompletely closed. FIGURE 7. The valve will then remain closed untilsuch time as the thermostat manipulator 42 is again turned to someselected temperature position for some future cooking operation, whichmay repeat the one so far described, or which may be a dilferent cookingoperation. The timer will be in knob position or off position, orcleared condition and the thermostat manipulator 42 will be in the offposition, both ready for some future use, as desired.

The user is continuously warned by the intermittent operations of thelight 98 and buzzer 184 as long as the manupulator 42 and knob 88 remainin the positions of FIGURE 4. Hence the user is not likely to faileventually to turn the manipulator 42 to ofi" position to terminate theentire timed operation.

Use of timer only without oven cooking, FIGURE 6 If the user shoulddesire to operate the timer 86 to indicate timed operations other thanthe operations performed in the oven 30, the positions shown in FIGURE 6may be used. For this purpose, the thermostat manipulator 42 is placedor remains in the off position and the timer knob 88 may be moved tosome timed position for the desired interval of time, such as position2. When this is done, the timer motor 112 drives the timer, so thehandle 88 gradually moves toward position 102, whereupon contacts 306,308 are closed and the buzzer 104 is energized through closed switches250, 252 and 300, 302 and 306, 308 and begins to sound and will continueto sound for 15 seconds while the handle 88 passes through zone 106 justbefore zero position 108. The buzzing sound terminates as the zone 196is passed. The timer motor 112 continues to run, however, until thehandle 88 reaches the olf position 90, whereupon the timer motor stopsand all operations are de-energized. In this manner the timer 88 hasbeen used to indicate any desired time interval in connection with anydesired operation, the end of which is indicated and warned by thesounding of the buzzer 104 for 15 seconds as the handle 88 passes thezone 1&6.

The thermostat unit 40 The thermostat unit 40 is particularlyadvantageous in connection with the control of pilot gas exclusively forthe pilot structure in a manner that the high volume gas to be used forthe main burner 36 does not pass through the working parts of the unit40, but rather flows through the pipe 38 outside the unit 40, or througha separate passage separate from the pilot controlling parts of the unit40.

The pilot gas enters through the pipe 48, FIGURE 1, and passes throughthe unit and leaves through the pipe 59 and enters the pilot 53 toproduce the small pilot flame 68, or the large pilot flame 55. Both ofthese flames are of use in connection with the ignition of the burner 6,but the volume of gas used by the pipe 50 is relatively small comparedwith the volume of gas which flows through the pipe 38 for the mainburner 36. For this reason, the working parts or pilot controlling partsof the unit 40 may be made of relatively small size, since unit 40 maybe made to handle only a small volume of pilot gas and yet efiicientlyto control the cycling of the main burner 36 without actually havingsuch gas pass through the working parts of the unit 40.

Referring first to FIGURES 1, 7 and 17 through 21, the pilot gas frompipe 48 enters through the inlet 48A of FIGURE 18 and passes through thepassageway 126 to the top of filter 128 and then passes downwardlythrough the filter 128 and past the adjusting key or pin 130 and throughthe passage 132, FIGURE 21, to the discharge outlet 134, whichdischarges pilot gas into the pipe 50 of FIGURE 1.

The filter 128 may include the usual filter cavity and filter unit ofwell known construction.

Another branch from the bottom of filter 128 passes through the passage136, FIGURE 19, and into the valve chamber 82, below the valve 76 ofFIGURE 7. When the valve 76 opens this pilot gas enters the chamber 84on the discharge side of the valve 76 and from thence flows through thepassage 138, past the adjusting key 140, FIGURES 20 and 21, from whichit passes to the outlet 134, which discharges into the pipe of FIGURE 1.The adjusting keys 130 and 140 may be turned through the adjustingopenings 144 and 146 respectively by means of the screw driver slots130A and 140A respectively in the threaded heads 13GB and 140B of pins130 and 140. The flow of pilot gas from the inlet 48A is indicated bydotted lines in FIGURE 17, which are marked with reference numeralscorresponding to the gas passages in FIGURES 18-21.

By this construction pilot gas to produce a small flame at pilot 53passes through inlet 43A, FIGURE 18, passageway 126, filter 128, pastadjusting pin 130, through passage 132, FIGURE 21., discharge outlet134, pipe 50 and pilot 53. The pin 130 is adjusted by slot 130A toproduce a gas flow to produce the small pilot flame 54. At this time, nopilot gas passes valve 76, FIGURE 7, since this valve 76 is closedbecause knob 42 either is in the off position or else the oventemperature in compartment $2 is in overshoot condition above thetemperature selected by the setting of manipulator or dial 4?; at someon position, such as 300. Hence the valve '76 is thermostaticallyclosed.

When the oven compartment 32 is at a temperature below the selectedtemperature on dial 42, the valve 76 is thermostatically opened andcauses higher volume pilot gas to flow through passage 136, FIGURE 19,valve chamber 82 past valve 76, FIGURE 7, chamber 84, passage 138,FIGURES 17, 20 and 21, adjusting pin 140, to outlet 134, pipe 59 andpilot 53. The volume and pressure in pipe 59 and pilot 53 are increasedby this higher volume pilot gas which passes valve 76 sufficiently toproduce the larger pilot flame 55. The pilot gas from outlet 134 andpipe 56 preferably passes through the same pilot orifice, whether thesmall flame 54 or the large flame 55 is being produced. The larger pilotflame 55 heats the thermostat bulb S7 and opens the gas valve 58 tointroduce burner gas from pipe or passageway 38 into the main burner 36.The burner 36 is then ignited by pilot flame 55.

When the compartment 32 starts to overshoot in temperature the valve'76, FIGURE 7, closes and reduces the flow of pilot gas in pipe 50 andpilot 53 so that pilot flame is reduced to size 54. This allows bulb 57to cool and close valve 58 to shut off the main burner gas in pipe 38from burner 36.

In this manner the thermostat unit 49 indirectly controls the feed ofmain burner gas to the main burner (or burners) 36 Without such burnergas passing through the working or pilot supply parts of the thermostatunit 43.

The pipe or passageway 38 may bypass unit 40 or it may pass through anenlargement in unit 41 for nonpilot working parts of the unit, asdesired.

The thermostat unit 46 may therefore be made relatively small but veryetiicient, as it may be produced to handle only a relatively smallamount of pilot gas for pilot flame use only.

Adjustment of thermostat arm fulcrum 72 The dial 42 of unit 41 adjuststhe fulcrum 72 of the thermostat arm by a combined rotary and axialmovement of the dial 412 and a corresponding combined rotary and axialmovement of the platform-like fulcrum 72. See FIGURES 1, 7 and 9-16.

FIGURES 1 and 7 diagrammatically show the dial 42, which is fixedlyconnected to and turns the outside threaded sleeve 170 which is inthreaded engagement with the stationary internally threaded cylinder 172of the cast body of the unit 40. The sleeve 170 is spot welded to thesleeve 174 onto which the dial 42 is slidably keyed in the usual mannerwith a snap action so the dial 422 is in rotationally fixed relation tothe sleeve .170. Rotation of the dial 4-2 rotates the sleeve 170, whichmoves axially by reason of its outside threads 176, which are indicatedon FIGURE 9. The sleeve 170 is also internally threaded at 178 toreceive the calibrat- 12 ing screw 180, FIGURES 7 and 13. Rotation ofthe screw 13:? moves or calibrates the screw 180 axially within thesleeve 170. The screw 1% abuts the end 181. of the f crum pin 182.

Ordinarily, the pin 182, which carries the fulcrum is held downwardlyagainst the end of the screw 1 by means of spring 234.

However, there are times when the pin 182 may is lifted upwardly, sothat its end 181 is moved upward" away from the end of the screw 180,and this takes place when the heat motor 114.- lifts the arm 118 and thefulcrum 72, as elsewhere described, or when the dial is turnedcompletely to the off position.

The sleeve has an axially expandable but rotationally fixed joint 18with the fulcrum pin 182. As shown in FIGURES 9, l0 and 11, the sleeve170 has slots 186 which receive key pins of pin .182, so the sleeve 17!]and the pin 182 are axially movable away from each other under certainconditions, but they are rotationally locked at the joint 184, which isformed by the slots 185 and the pins 188.

The fulcrum pin .182 has a supporting platform which has an extension orlip 15 2 which is rounded at the bottom, as shown in FIGURE 12. Theplatform 190 and the extension 192 move above the supporting surface194, FIGURES 14, 15 and 16 of the cast body 191 of the unit 45 Theextension 192 engages the lifting earn 196, FIG- URES l5 and 16, as thedial 42 is being turned toward the of. position, so the fulcrum 72 isquickly raised by the cam 1915 and finally slides over the hump 193 intothe lock groove 26%). The hump 198 allows the extension 192 to be movedeither in or out of the groove 2%, but imparts a feel or slightresistance and give which the user feels when the knob enters or leavesthe locked position. The larger hump 2G2 prevents the knob 42 from beingturned beyond the off position in either direction.

It is thus to be seen that the fulcrum pin 182 may be slidably raisedwith respect to the sleeve 17%, both by the action of the heat motor 114and by the turning of the knob to the locked off position, whichproduces a faster upward movement of the pin 182 than is produced by theexternal threads of the sleeve 170.

The heat molar 114 The heat motor 114 may be made insertable in andremovable from the main casting 191 of the unit 40. If desired, the unit48 may be used or produced without the heat motor 114. For this purpose,a casting or plate 298, FIGURE 7, forms the bottom of the heat unit 114and the same may be secured to the main casting 191 of the unit 46 bymeans of the screws 21%, FIGURES 7 and 8. The base 2118 has a circularplatform 2132 which is surrounded by a helical spring 214 and whichupwardly pushes an insulating body 216, which carries the heater 116 andthe double-walled, expandable diaphragm 213' which may contain a smallamount of water or the like which is heated by the heater 116 to expandthe same. A ball 22% is welded to the upper membrane of the diaphragm218. The lower web of the diaphragm 218' is supported by the head 222 ofthe screw 224 which is screw threaded on the base 298 for adjustment asto height of the diaphragm 218'. A screw driver may be inserted in theslot 219 for this adjustment. The heater 116 has prongs 226 forconnection of the leads of the wires 116A and 324A shown in FIGURE 4.

The upward movement of the lever 118 is limited by the limit pin 124.The lower end of the pin or screw 124 is screw threaded at 125 andreceives the sleeve 228 which is internally threaded to receive theexternal threads 125 of pin 12 The sleeve 228 is externally threaded toengage internal threads at 229 in the cast body 2118 of the heat motor.A slot 231} (shown in transverse cross section in FIGURE 7) is providedin sleeve 228 to receive a screw driver so the pin 124 may be adjustedvertically by turning the sleeve 228 with the screw driver in slot 230.The

13 height of the pin 124 may be changed by the rotation of the sleeve228 to provide the right height for the head of the screw 124.

The external threads 229 in sleeve 228 are of a greater pitch than thatof the internal threads at 125A so that the axial movement of sleeve 228dominates the combined axial movement of sleeve 22% and pin 124.

The pin 124 may be keyed at 12 2A by making the pin 124 rectangular atthat point to prevent rotation of the pin 124.

The lever 118 has a rounded double-prong fork 232 which straddles thefulcrum pin 182 and presses upwardly against the under surface of thefulcrum disc 72 to raise the pin 182 and fulcrum 72 when the heat motoris heated.

The thermostat lever 76' is pressed downwardly by a relatively strongaction of the spring 234 at one end and is attached to the spring 236 atthe other end. The spring 236 is forked at its right end, FIGURE 7, andbears downwardly against the lever 11% and holds the lever 118 downwardunder spring action. The ball 238 is welded to the diaphragm 6t andbears against the thermostat lever 70.

The heat motor 114 has the body 216 made of insulating material and thecast body 228 which may be made of metal. These bodies are received inthe cavity 227 in the main casting 191 of the unit 4t). An opening 229is provided in the main casting 191 of the unit for access to theconnectors 226 of the heater 116, etc.

The switches 240 and 264 A multiple pole switch 241 is operated by anextension of the fulcrum pin 182, which is diagrammatically indicated bythe line 242. This extension 242 is moved with, attached to, or integralwith the top of the fulcrum pin 182. The extension 242 moves theinsulating piece 244, FIGURE 1, of the switch 249 so the contacts 246and 248 are closed whenever the dial 42 has been moved away from the oifposition to an on position. At that time the contact 25% is open, as inFIGURE 2. However, when the dial 42 is turned to the off position thenthe contact 25!) is closed with respect to a contact 252, as in FIG- URE6.

Another extension 254, FIGURE 7, which is indicated by a line extendingfrom the top of rod 79 immediately above the ball or end 74A of theplunger 74 and may extend through a sleeve or the like 256, FIGURE 7,and has a relatively stiff blade or the like 258 which moves thebendable leaves or blades which carry contacts 266 and 262 of the switch264.

The positions of this switch 2% are shown in FIG- URES 22, 23 and 24.The leaf of contact 269 is movable upward, while the leaf of contact 262remains stationary, as shown in FIGURE 22 when the thermostat lever 70is in the off position of the dial 42 or when the thermostat arm 79 isin an overshoot position, as when the oven has slightly overheated andthe bulb 56 has caused the diaphragm 68 to press downwardly beyond thepossible upward travel of the plunger 74 when the valve 76 has closedand limited the upward movement of the plunger 74. In the off positionof dial 42 the lever 70 is moved upward far beyond the uppermostposition of the plunger 74 by the camming action 196, FIGURES 14, 15 and16, elsewhere described.

FIGURE 23 shows the switch 264 closed at the time that the valve 76 hasjust closed or just opened. That is, the switch 254 is closed on theadjacent up or down temperature movement of ball 74A near the selectedtemperature setting when the valve 76 has contacted its seat because theoven has just reached the Selected temperature or is just about to leavethe valve seat.

FIGURE 24 shows the switch 254 opened by the downward movement of theleaf of contact 262 while the leaf of contact 2619 remains stationarywhen the lever 7 t is in an undershoot or cold position below theselected temperature level indicated by the line 266 which would 14 bethe level of arm 70 shown in FIGURE 23. The actions of these switches240' and 264 become apparent from other descriptions concerning thewiring connection with the timer, switches, of the timer 86.

Many features of this invention may be utilized by using an electricswitch, or substituting an electric switch, for the valve construction76, 80. Such a switch may be closed on the down position of the plunger74 or equivalent structure and may be opened on the up position of suchplunger 74. The substituted switch may itself control electric heatersfor the oven being controlled or for any other heating system being socontrolled. Alternatively, such a switch may in turn control a relaywhich in turn controls the heaters so described, or a relay gas valveconstruction.

Descriptions of the circuits of FIGURES 1-6 The electric circuits ofFIGURE 1 may be traced from the line L to the connecting pin La ofswitch 240. The closed contacts 246 and 247 energize the line 246A,light and trunk line 1 A of terminal L The light 100 indicates that theoven is on and is being heated under control of thermostat unit 49according to the setting of manipulator 42. The failure of the light tobe illuminated indicates that the timer control is not being used and isat OFF.

Another circuit of FIGURE 1 may be traced from line L through closedcontacts 248, 248, line 243A to closed contacts 313, 320 of upwardlymoved Switch 94, then through line 260A to oscillating contacts 269, 262of switch 264, to line 262A, oscillating light 98, and line L A. Thelight 98 illuminates when thermostat arm 7i] is at or near the selectedtemperature position, such as 300, as in FIGURE 23, and extinguisheswhen the arm 70 is in overshoot, FIGURE 23, undershoot or coldpositions, FIGURE 24, as elsewhere explained, in connection with FIGURES22, 23 and 24. Oscillation of light 98 indicates that the oventemperature is being oscillated back and forth past the selectedtemperature by the h rmostat. The light 98 also remains dark from a coldstart until the oven first reaches the selected temperature, and isready for the insertion of food in the oven.

In FIGURES 1-6 inclusive, cross hatched circles on certain switchblades, such as the blades having contacts 246, 248 and 250, areintended to indicate diagrammatically that such blades are arrested intheir movement so the cooperating contacts, such as 246, 248 and 252 maybe separated, to open the circuit at that point. The blades so arrested,however, may have a limited flexing movement, if desired, as is wellunderstood, as long as the respective circuits may be opened at theattached contacts.

The electric circuit for FIGURE 2 may be traced from power line L to Laand through closed contacts 246, 247, line 246A, light 100, and line LA. Another branch from 246A goes to contacts 312, 310 to light 110 andto line L A. Illuminated light 110 indicates that the oven is on, andthat it is being automatically controlled by the unit 40 and the timer86. Light 100' indicates that the oven is being heated under the controlof thermostat unit 40.

In FIGURE '2, another branch extends from power line L,, La, throughcontact 248', 248, line 248A, closed contacts 314, 316, line 112A, timermotor 112, and line L A. This latter circuit energizes the timer motor112 to drive the timer knob 88 and switches moved thereby toward the offposition 90.

The circuit of FIGURE 3 is the same as FIGURE 2, except that thecontacts 306, 308 are closed while the knob 38 is passing through thezone 1%. The closing of these contacts causes the buzzer 104 to soundand thus to indicate that the thermostatically and timed controlledoperation of FIGURE 2 is about to end, substantially after a fifteensecond sounding of the buzzer 104. The buzzer 104 may be of any desiredloudness and of any desired tone quality, and it is adapted to be heardreadily by the user while in the neighborhood of the kitchen.

The circuit of FIGURE 4 is partially the same as that of FIGURE 2. It isthe same insofar as illumination of lights 100 and 10 is concerned, anddescription of these circuits is not again repeated. The light 93 isintermittently illuminated and darkened under the control of the closingand opening of the switch 264 as the thermostat arm 70 oscillates backand forth over the selected temperature position, such as 300. Thisaction of switch 264 is more fully described in connection with FIGURES22, 23 and 24. The oscillating illumination of light 98 is powered fromline L through contacts 248, 248, line 248A, contacts 220, 218, line260A, switch 264, line 262A, light 98, and line L A. The buzzer 104 isintermittently powered in parallel with the light 98, since the line262A of light 98 is extended at 26213 which energizes the closedcontacts 326, 328 and line 328A which is connected to the buzzer 104while the buzzer is also connected on the other side to the line L A. Inthis manner, the buzzer 104- is intermittently energized by the openingand closing of the switch 264 as long as the knob 88 of the timer 36remains in position 103. This is a continuous warning that the highertemperature heating period has terminated, and that a lower temperatureheating period will continue until the circuit of FIGURE 4 is altered bythe user.

When the timer knob 88 reaches the position 108, as in FIGURE 4, theline 112A is de-energized because all connections with the powercontacts 246 and 248 are roken by the upward movement of the switch 94when the knob 88 reached the position 108.

However, the upward movement of the switch 94 energizes the modifyingunit 11.4. If such unit 114 is a heat motor, the energization takes theform of the energizing of the electric heater 116. Power for the heater116 is provided from L, La, through contacts 247, 246, line 246A, closedcontacts 312, 310, closed contacts 322, 324, line 324A, heater 116, line116A and line L A so the heater 116 is energized.

The energization of the heater 116 causes the arm 118 to be raised,which in turn raises the fulcrum 72 and causes the thermostat unit 40 tooperate at a lower or modified condition as long as the knob 88 remainsat 108. However, when the knob or manipulator 42 is moved to the offposition, the power to the heater 116 is broken at the switch 240 andthe timer motor 112 is energized, as shown in FIGURE 5.

The circuit of FIGURE 5 occurs when the manipulator 42 of FIGURE 4 ismoved to the off position as in FIGURE 5. This movement may be producedby the user and causes the switch 240 to be moved to the up a positionby the upward movement of the manipulator 42 and pin 182 and thisde-energizes contacts 246 and 248 and disconnects all the circuits tothe unit 40 and to the lights 98, 100, 110 and to the buzzer 104. Thisindicates that the thermostat unit 40 has been turned off and that i thetimer will be or has been automatically turned to off position 90.

The upward movement of the switch 240 closes the contacts 250 and 252 sothe line 250A is energized from connector La and the power line L Theline 250A energizes the closed contacts 300 and 302 which in turnenergize the timer line 112A as well as the timer motor 112 which isconnected to the line L A. This causes the timer motor 112 to drive theknob 88 and switches connected thereto from the position 108 to position90 as soon as the manipulator 42 has been moved to the 011 position, asshown in FIGURE 5.

In the timer only position of FIGURE 6, the timer 86 is used to indicatea selected period of time for the timing of some device or operationother than the thermostat unit 40. The timer knob 88 is set at aselected time above zero, such as at position 2. The timing motor 112 isenergized through the closed contacts 250, 252 on the oven switch 240through energized line 250A, and closed 16 contacts 300 and 302, throughthe line 112A, timer motor 112 and line L A. The switch 96 is in thedown or closed position at all positions of the pointer 88 of the timer86, except at the otf position 90, at which time the insulator orsimilar structure 304 of switch 96 is moved to the up dotted lineposition shown in FIGURE 5 to open the contacts 300 and 302. Therefore,the timer will run from the position 2 to the position 90 where theswitch 96 opens. The switch 92 of the timer 86 has its contacts 306 and308 open at all times of the position of the timer knob 88 from 2 to 90,except While the knob 88 is passing through the zone 106 from theposition 102 to the position 107. The switch contacts 306 and 308 ofswitch 92 move to the closed position during a fifteen second periodCombined timer and thermostat operation The combined timer andthermostat automatic operation is illustrated in FIGURES 2, 3 and 4.

In FIGURE 2, the manipulator 42 has been placed at some on position,such as 300, and the timer knob 88 has been placed at some intervalposition, such as 2. This closes the contacts 247-246 and the contacts248-248 of switch 240 by the on position of the knob 42. The posi--timing of the knob 88 at 2 or some other interval position, such as 3 or4, maintains the contacts 310 and 312 of switch 96 in closed or lowerposition, which have become live by the closing of the contacts 247 and246 and this lights and energizes the lights 100 and Also, the contacts314 and 316 of switch 94 are in closed or lower position while the knob88 is moving from position 2 to a position just before 108, so thecontacts 314 and 316 energize the timer motor 112 to drive the knob 88from the position 2 to the position just before 108. While the timerknob 88 passes through the zone 106, as illustrated in FIGURE 3, thebuzzer 104 is energized by the closing of the contacts 306 and 308. Thecircuit of switch 264 is not operable or energizable during this period,as its circuit is interrupted because of the open contacts 318 and 320of switch 94 of the timer 86.

When the timer knob 38 reaches the zero position 108, the circuits areenergized as shown in FIGURE 4. At this time the switch 94 is moved tothe upper position to close the contacts 318 and 320 and also thecontacts 322 and 324. The contacts 306 and 308 are opened after the knob88 has passed the zone 106. The timer motor 112 is deenergized as thereis no circuit closed to this motor.

In FIGURE 4, the heat motor 114 is energized to heat the heater 116 andthe circuit of the switch 264 and its closed contacts 260 and 262 isenergized because of the closing of contacts 326 and 328 of switch 96,as well as i the closing of contacts 318 and 320 of switch 94. Theenergizing of the circuit of switch 264 causes the light 98 to be turnedon and off as the arm 70 of the thermostat passes back and forth overthe selected temperature level or the upper position of plunger 74, asmore fully elsewhere explained in connection with FIGURES 22-24. Whenthe cooking operation has reached the stage of FIGURE 4, the oven shouldbe at the selected temperature or at the upper position of plunger 74and the switch 264 will be closed, so that the light 98 is energized andthe buzzer 104 will be energized through closed contacts 326 and 328.The heat motor 114 throws the thermostat unit 40 to a lower temperaturesetting as is elsewhere described and in so doing it throws thethermostat arm 70 into overshoot. This opens the switch 264 so currentto the light 98 and the buzzer 104 is momentarily interrupted. Themomentary signals from the light 98 and the buzzer 104 combined with theprevious fifteen second operation of the buzzer 1G4 combine to warn theuser that the dinner will be complete in about to minutes. This allowstime to perform the finishing touches for the dinner. When the ovencools to the fixed lower temperature, the switch 264 will come out ofovershoot and will close and Will complete circuits to the light 98 andto the buzzer 104. This tells the user that the operation has beencompleted and that the dinner is ready. The timer will remain at zeroand the oven temperature will remain at the reduced level caused by theheat motor 114 until the thermostat knob is turned to the ofi position.

The continued intermittent actuation of light 98 and buzzer in FIGURE 4warns the user that eventually the thermostat manipulator 42 should beturned oif.

At the thermostat manipulator 42 off position the timer will clearitself and the knob 88 will move to off position 90 through the closingof contacts 250 and 252 of switch 240. The operation of the timer motor112 will be stopped when the switch 96 is pushed by the timer to theopen or top position, as indicated in dotted lines in FIGURE 4.

The next time the thermostat knob 42 is turned on, it will be a manualoperation, as shown in FIGURE 1, and the operation will be as shown inFIGURE 1, unless the knob 83 is again also turned to some timingposition, such as 2 of FIGURE 2.

If the thermostat unit 49 is provided with a return motor for returningthe knob 42 to the oif position by the energization of a circuitcorresponding to the circuit of heater 116, then the thermostat unit 4%will be turned to the off position by the motor, to the positions shownin FIGURE 5, and the timer 86 will be energized until such time as theknob 88 is in the position 90, at which time the timer will turn itselfofi by moving the contacts of switch 96 to the dotted line openposition.

However, if the heating unit 114 is being used as in the operation justpreviously described, the timer 86 will be driven by the closed contacts252 of switch 240' when the manipulator 42 is turned manually by theuser to the off position and this will energize the motor 112 to drivethe knob 83 to the off position 99, 'at which time the timer will movethe switch 96 to the up position and so deenergize itself by stoppingthe motor 112.

The timer construction FIGURES 25 and 26 show diagrammatically detailsof the timer construction.

FIGURE 25 shows diagrammatically the knob 88 of the timer 86, with thediagrammatic cam construction 450 movable therewith in fixed relation.The cam construction 450 may be a single cam or a plurality of cams,which is capable of producing the relative movements shown in FIGURES 1to 6 between the knob 88 and the switches 92, 94 and 96. Any suitabletype of timer con struction may be used that produces this result.

For example, a single cam 450 may be used which has a peripheral surface452 which actuates the roller 454 and the ball crank 456, 458 which ispivoted about the fulcrum 460.

The knob 88 and cam 454 are fixedly secured to the rotatable shaft 481}.

When the roller 454 is riding on the surface 452, which is a positionnot illustrated in FIGURE 25, then the arm 453 is slightly to the leftof the position shown in FIG- URE 25. The switch is in the off position90, in FIGURE 25. The knob 88 is shown in the off position in FIGURE 25,which corresponds to position 90 in FIGURE 1. The roller 454 is ridingon the periphery at a point which is the highest that the roller 454 isnormally moved. This is the greatest radius distance used from thecenter of cam shaft 486.

With the knob at the position illustrated in FIGURE 25, and with theroller 454 near the top of the hump 462, the pushing member 464, whichis moved by arm 458, has pushed the arms 466 of the switch 96sufiiciently i8 far to the right so that the arms 466 cause the switch96 to be in the up position shown in FIGURE 1. Under these conditionsthe switch 96 stops the timer motor 112.

When the knob 88, in FIGURE 25, is moved counterclockwise to some suchposition as 2, as indicated in FIG- URE 2, the cam 450 likewise is movedcounterclockwise, from the position of FIGURE 25, so that the periphery452 is placed under the roller 454 to move the roller 454 to a lowerposition, and to cause the arm 458 to move leftward along with thepusher 464. This moves the arms 466, 468 and 4'76 of switches 92, 94 and96 all leftward, to cause the switches 92, 94 and 96 of FIGURE 25 toproduce the switch positions of switches 92, 94 and 96, of FIGURE 2, inwhich FIGURE 2 all of these switches are in the down or normal position.

The knob 88 and cam 450 then begin to be driven clockwise under thedriving action of timer motor 112 until the knob 88 reaches the zone106, as shown in FIG- URE 3. When the knob has moved to this position ofFIGURE 3, then the cam 450 of FIGURE 25 has moved, so that the lowsurface or zone 106 of the cam 450 is under the roller 454. The arm 458is then in its most leftward position zone, which moves the arms 466,468 and 470 to their most leftward position zone. The switches 94 and 96are not altered by this motion, but the switch 92 is changed to theclosed position of contacts 306 and 308, as shown in FIGURE 3, so thebuzzer 104 is sounded, during the passage of knob 88 through zone 166.

When the knob 88 reaches the position 168, of FIG- URE 4, then the cam459 places the surface 472 under the roller 454, which moves the arm 458and pusher 464 rightward from the position they had when the rolier 454was over the low valley 106 of the cam 450. The radii of surface 4'72are greater than the radius of cam surface 452. This moves the arms 466,468 and 470 slightly rightward beyond the positions which they had whenthe roller 454 was riding on the surface 452. The pusher 464 then movesthe arms 466, 468 and 470 to a position such that the switches 92, 94and 96 have the position of FIGURE 4, wherein the switch 94 is in upposition, and the switches 92 and 96 are in the down position. Thisproduces the action elsewhere described in connection with FIGURE 4.

When the thermostat manipulator 42 is moved to the off position, asshown in FIGURE 5, then the timer motor 112 drives the knob 88 and cam450 so the knob 88 starts to move rightward toward the position 90. Thecam 456 moves slightly clockwise in FIGURE 25, so that the roller 454starts to move up the incline of the hump 462 toward the position 90.During this time the motor 112 is energized to drive the cam 450 untilthe cam surface raises the roller 454 sufiiciently high so the pusher464 is moved rightward and the arms 466 also are moved rightward asutficient distance to cause the switch 96 to assume theoif position ofFIGURE 1. The switch 96 is in the up position to produce the conditionswherein both the manipulator 42 and the knob 88 are in the off position,with the entire system de-energized.

The switches 92, 94 and 96 illustrated in FIGURE 25 may be of anydesired type capable of producing the contact positions described inconnection with FIGURES 1-6. Such switches may be slow make and breaktype, or of the snap acting type. They may be actuated by the levers466, 468 and 475 to produce the desired contact conditions. Switches ofthis type are well known and are produced by switch manufacturersaccording to the requirements of the user.

FIGURE 26 shows a diagrammatic side view of the timer of FIGURE 25 ingreatly reduced scale. The body or the switch is indicated at 86 inFIGURE 26, with the knob 88 on driving the shaft 430, which is fixed tothe knob 88, and to the earn 450 of FIGURE 25. The construction is suchthat movement of the knob 88 causes an equal movement of the cam 450,and shaft 480. I

A slip clutch or the like 482 produces a slip action between the gearwheel 484 and the shaft 480. The gear wheel 484 is loosely mounted onshaft 480. The knob 88 and cam 450 may be rotated by the user withoutnecessarily causing any rotation of the motor 112. This is particularlyadvantageous where there is a large gear reduction between the rotationof the motor 112 and the shaft 480.

By way of example, the spring discs or fingers 436 and 488 are fixed tothe right end 490 of the shaft 480 but have a slipping engagement withthe sides of the loosely mounted gear 434, so that the shaft 480 may berotated along with the spring discs 486 and 438, without neces sarilyrotating the gear 484 and the motor 112. Any other type of slip clutchconstruction may be used for this purpose.

This type of construction permits the user to rotate the knob 88 and cam450, counterclockwise in FIGURES l and 25 quickly and withoutnecessarily rotating the motor 112. Thereafter, the motor 112 may drivethe gear 484 and shaft 480 clockwise in FIGURES 1 and 25 through reducedspeed gearing and through the slip clutch 438 to return the knob 88 andearn 450 to or toward the off position 90 as elsewhere described. Therelatively low torque required to rotate the shaft 480 permits the motor112 to drive the shaft 430 through the slip clutch 488 except whenopposed by manual actuation of the knob 38, or when stopped in the offposition 30 by the hump 462 of FIGURE 25.

FIGURES 27 through 33 show a simplified diagram and embodiment in whicha unit 400 of any kind, such as the thermostat unit 40 heretoforedescribed, may have a unit manipulator 461 with an off position 402,FIGURE 33, and one or more on positions 404, such as manipulator 42.

The switch means 406, FIGURE 28, (such as switch 240 of FIGURE 1) isoperated by movement of the manipulator 401, FIGURE 33, from said onposition 404 to said off position 402. The switch means 406 in FIGURE 28has a first switch 408 closed (diagonal lines across the switchesindicate closed condition) when said manipulator 401 is in off position401. A second switch 410, FIGURE 28, is open (with no diagonal linecrossing it) when said manipulator is in the off position 402. The firstswitch 408, FIGURE 29, is open and said second switch 410 is closed whensaid manipulator 401 is in the on position 404.

A timer 412 has a knob 414 with an off position 416 and a plurality ofon positions 418, 420, 422, 424, 428 and 430.

Third, fourth and fifth timer switches 432, 434 and 436 respectively,FIGURES 28-32, are provided for the timer 412 and they are actuated by aswitch actuating means in the timer 412, not shown, to operate theswitches 432, 434 and 436 in accordance with the positions of the knob414. A timer return motor 438 returns the knob 414 from any of said onpositions toward and to said off position 416, in a manner similar tothat disclosed in FIGURES 25 and 26. The knob 414 is manually movablefrom said oil position 416 to a unit modifying position 420 and to anormal zone of timed normal unit operation which may include allpositions counterclockwise of position 416 and on through to position430. A modifying circuit including member 437 is in modifying condition,as shown in FIGURE 30, when the knob 414 is in modifying position 420.The circuit is in non-modifying condition at all other knob positionsoutside of the zone produced by positions 418 and 420, such zone beingindicated by the reference numeral 419.

In FIGURE 28, the timer knob 401 is at 416. The thermostat dial is atoff. The timer motor 438 is deenergized. The circuit including member437 is de-energized.

In FIGURE 29, at the start of the timed operation, the thermostat dial412 is at on. The timer knob 414 is in 2% zone 420-430. The timer motor438 is operating. The auxiliary circuit 437 is de-energized.

In FIGURE 30 at the elapsed time position, the thermostat dial 401 ison. The timer knob is at zero, i.e., 420. The timer motor isde-energized. The auxiliary circuit 437 is energized.

In FIGURE 31, the operation is complete. The timer knob is at zero,i.e., 420. The thermostat dial 401 is at oif. The timer motor 438 isoperating. The auxiliary circuit is de-energized.

In FIGURE 32 the timer knob is clearing, i.e., is returning to 416. Thetimer knob is at 418. The thermostat dial 401 is off. The timer motor438 is operating. The auxiliary circuit is de-energized.

The combined operation with the manipulator 401 in the on position 404and with the knob 414 in the normal zone from just counterclockwise of420 and on through to 430 actuates the switches to cause the unit 400 tooperate in normal unit operation and causes the knob 414 to be moved orreturned by timer motor 438 to the said unit modifying position 420where the unit 400 is modified and is maintained modified betweenpositions 420 and 418.

The timer knob 414 is operated and moved by the timer motor 433 to theOE position 416 from any on the positions 420 to 413 when the unitmanipulator 401 is moved to the manipulator off position 402.

If desired, in the construction of FIGURES 27 through 33, the unit 400being controlled and which has the manipulator 401 may be modified byautomatically driving the manipulator 401 from the on position orpositions 404 to the off position when the timer knob 414 reaches themodifying position 420.

The invention disclosed in FIGURES 27 through 33 incorporates anelectrically driven timer 412 with attached switches 432, 434 and 436 ina fixed relation to the timer knob 414. The timer switches 432, 434 and436, are indicated variously in open and closed position in FIG- URES 28through 32 being closed when a diagonal line crosses them and being openwhen there is no diagonal line. The timer knob 414 can be manually setto any position counterclockwise from the off position 416. Whenenergized, the timer motor 438 will drive the knob 414 from a high to alower indicated position.

A single pole, double throw switch 406 that works in conjunction withthe unit 400 such as an oven thermostat is another component of thisinvention. This switch is indicated at 406 by contacts 408 and 410.

FIGURE 28 shows the switch contacts 432, 434, 436 in their off position416. Any time the unit or thermostat manipulator 401 is turned to theoftposition, the system will return to this position 416.

This invention is operated by turning the unit or thermostat manipnlator401 to on position 404 while the timer knob 414 is turned to someposition above or counterclockwise to 416. The contacts then assume thepositions shown in FIGURE 29, and the timer motor 438 operates to movethe knob 414 toward 0 or 416. The auxiliary function circuit 437 is notenergized at this time because of open switch 436.

The timer moves from the selected position to 0 time 420 where the timermotor 438 is de-energized by open switches 408 and 434 as the contactsassume the position shown in FIGURE 30. Contact 436 is shown to close atthis elapsed time position. Contact 436 could be closed at some positionabove the 0 position 420 if it is desired. This closed contact 436energizes an auxiliary circuit 437 that could be used for a signal, acomplete interruption of oven heat, or a reduction in oven heat. Thetimer knob 414 stays at 0 or 420 and the contacts stay as shown inFIGURE 30 until the operation is complete and the unit manipulator 401is turned to the off position 402. The manipulator 401 may be turned tothe off position manually by the user, or alternatively by a returnmotor, not shown, on manipulator 401. Contact 408, FIGURE 21 31, thencloses to re-energize the timer motor 438 through contact 432, as shownin FIGURE 31.

Contact 436 opens at the timer dial position 418, FIGURE 32, tointerrupt the auxiliary function circuit 437 as the timer clears itselfas it is moving toward position 416, as shown in FIGURE 32.

The timer motor runs until the knob returns to the off position 416where the contact 432 opens, as shown in FIGURE 28. The system has thencleared or deenergized itself. When the thermostat or unit is usedagain, the timer and the timer holding circuit will not operate unlessit is reset to some position counterclockwise from position 416.

If the timer 414 is set to an operating position above orcounterclockwise from position 416, without turning the thermostat orunit manipulator 401 to the on position 464, the timer will return toits off position 416 and performs a timing operation entirelyindependent of the unit or thermostat which is controlled by themanipulator 401.

In order to obtain an alternate type of operation, contact 408 could bea single pole, single throw switch working in conjunction with thethermostat dial 401. This switch 408 would close only when thethermostat was turned to the off position 492. This position isidentical to that previously described for contact 468. Contact 410 canbe a separate switch from contact 408. The most likely possibility wouldbe to use a ready switch for contact 419. This switch 410 would closeonly when controlled temperature has reached the indicated temperatureof the thermostat manipulator 401, and would open at the thermostat offposition 402. This alternate system would then allow the timer motor tostart only after the controlled temperature had reached its set point.This difiers from the previously described system where the timer motorwas energized by turning the dial counterclockwise above position 416.

One timer of the type described above could be used in conjunction withmore than one thermostat. This would be done by means of a selectorswitch that would disconnect one thermostat while connecting another.

The system described in this disclosure would clear itself only in theevent that the thermostat or timer were turned to off. Once the systemhas started to automatically reduced temperature, it is necessary toturn the thermostat off before it is possible to perform another cookingor baking operation. This operation is less complicated thanconventional clock systems where it is necessary not only to perform theusual operation of turning the thermostat otf, but the clock must alsobe reset to manual.

It is to be noted that thermostat arm 70 may be provided with downwardbulges 72A, FIGURE 7, to rock on the upper surface of fulcrum disc 72.

It is thus to be seen that a relatively simple and efiicient system hasbeen provided and that relatively simple components which may be used insuch a system have also been provided.

A relatively simple and efficient thermostat unit 40 has been provided.This unit may include modifying components which may be added to oromitted from the thermostat unit as required by the purchaser. One ofthese modifying components may be, for example, a temperature settingmodifier which may be electrically energized and may be a heat pump,solenoid construction, and the like. Another of these modifyingcomponents may be a manipulator return motor and the like which may beprovided with or omitted from the thermostat unit.

Both the temperature setting modifier and the manipulator return motormay be provided on the same thermostat unit and a two way selectorswitch may be included in the modifier electric circuit 324A and 116A ofFIGURE 4 so the user may selectively choose whether the temperaturesetting modifier 114 shall operate during a given cooking operation toreduce or increase the temperature or whether the manipulator returnmotor shall operate completely to de-energize both the thermostat unitand the timer unit 86 with which the thermostat unit may be connected.

The thermostat unit 46 is so constructed that it may causethermostatically controlled operation of the gas burning elements of theoven 30 whether the electric power is available or not. The oven may bethermostatically controlled even when there is an electric power failuredue to a storm and the like.

The thermostat unit 40' may also be provided to a customer with orwithout the switches 240 and 264, depending on whether the customerdesires to use or omit the timer 86 in his equipment.

The timer 85 may be used to control or indicate the operation of thethermostat unit 40', or to indicate the period of operation of any otherunit or device which may be operable in the neighborhood of the timerunit 86.

These and many other advantages have thus been provided by thisinvention.

While the form of the invention now preferred has been disclosed asrequired by the statutes, other forms may be used, all coming within thescope of the claims which follow.

What is claimed is:

1. In combination, a thermostat unit having means for thermostaticallycontrolling the heating operation of a heating means in response to thetemperature effect of said heating means, said unit having a temperatureresponsive device provided with a wall part that moves in response totemperature changes sensed by said device, a manipulator means formanually setting said thermostat unit to select the temperature effectto be maintained without varying the position of said movable part ofsaid temperature responsive device, and a heat motor to be energizedduring the operation of said heating means to adjust said thermostatunit to a different setting thereof without varying the position of saidmovable part of said temperature responsive device, said manipulatormeans being adapted to set said thermostat unit in its off position tostop the operation of said heating means before and after said heatmotor has adjusted said thermostat unit to said different settingthereof. I

2. A combination as set forth in claim 1 and including conditionresponsive means for energizing said heat motor.

3. A combination as set forth in claim 2 wherein said conditionresponsive means is a timer means.

4. A combination as set forth in claim 1 wherein said heating meanscomprises a burner means for fuel.

5. A combination as set forth in claim 1 wherein said heat motor adjustssaid thermostat unit independently of said manipulator means.

6. A combination as set forth in claim 1 wherein said manipulator meansis rotatable.

7. In combination, a housing having a valve seat, a valve member foropening and closing said valve seat, a fulcrum pin means axially movablein said housing, manual means for adjusting the position of said pinmeans, a lever fulcrumed on said pin means and being operativelyinterconnected to said valve member, a temperature responsive devicecarried by said housing and having a wall part that moves in response totemperature changes sensed by said device, said movable part engagingsaid lever to fulcrum said lever on said pin means to vary the positionof said valve member relative to said valve seat in response totemperature sensed by said temperature responsive device, and a heatmotor for adjusting the position of said pin means when said heat motoris activated without varying the position of said movable part of saidtemperature responsive device, said manual means being adapted to movesaid pin means to its off position to close said valve member againstsaid valve seat before and after said heat motor has adjusted theposition of said pin means.

